Wa n al o f W u r s t e
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ISSN: 2252-5211
International Journal
Ayo et al., Int J Waste Waste Resour 2017, 7:2 DOI: 10.4172/2252-5 10.4172/2252-5211.1000281 211.1000281
of Waste Resources
RResearch e s e a r c hArticle A r t ic le
O pInternational en A cc ess OMICS
Development of a Waste Plastic Shredding Machine Akinfresoye Waleola Ayo*, Ayo*, OJ Olukunle and DJ Adelabu Department of Agricultural and Bio-Environmental Engineering Technology Technology,, Rufus G iwa Polytechnic, Owo, Ondo State, Nigeria
Abstract Plastic is one of the most common used materials in the world today, but, they cause serious environmental pollution and exhaustion of landll space. The recycling of waste plastic recovers the material, which can be used to make new plastic products such as containers, plastic lumbers and particle boards. For this to happen, the waste plastic will rst be shred into small bits making it ready for transportation and further processing. This necessitated the development of a plastic shredder to recycle the waste plastic found in Federal University of Technology, Akure (FUTA), Ondo State, Nigeria environments. The shredder has the feeding unit, the shredding unit, power transmission unit and the machine frame. The performance of the machine was evaluated and test results showed that there was a correlation between the machine speed with a regression < 1 and there was a linear relationship with all variable parameters (The Shredding time (T), the Specic Mechanical Energy (SME), Throughput (TP) and Recovery Efciency (RE)) and the variable operation speeds (1806.7 rpm, 1290.5 rpm and 1003.7 rpm). The throughput of the machine is 27.3 kg/hr and the efciency is 53% for all type of plastic and 95% for Polyvinylchloride type of plastic. The machine is user friendly and the cost of producing one unit of the machine as at the time of fabrication was estimated to be One Hundred and Forty Thousand, Seven Hundred and Fifty Naira (N 140, 750:00k) only making it affordable to acquire for small and medium scale entrepreneurs in waste plastic recycling business.
Keywords: Development; Plastic; Shredding; Machine; Waste Introduction Plastic have become an essential part o our day to day lie since their introduction over hundred years ago [1]. It is one o the most commonly used materials in the world today [2]. Tey come in five major categories; the Polyethylene terephthalate (PE), the High density polyethylene (HDPE), the Polyvinylchloride (PVC), the Polypropylene (PP) and the Low density polyethylene (LDPE). Te huge quantities quantities o these plastic categories currently being marketed will ultimately find their way to the waste dump sites [3]. Tis is creating waste products problems due to its high amount o waste generated, non-biodegradability and the astest depletion o natural resources regarding its short lie cycle, thereore increased amount o material utilized in its production, and waste generated [4]. Plastic bottles make up approximately 11% o the content landfills, causing serious environmental environmental consequences [5]. Te plastic waste g lobally constitutes more than 60% o the total global municipal solid waste (MSW), 22% were recovered and 78% disposed [6]. In United States, the waste o plastics in 2005 was calculated as 11.8% o the 246 million tons o MSW generated [7]. Some states in the US like Michigan have a recycling rate that is close to 100% and in Brazil, some potential in recycling have been raised where around 15% o all plastics consumed are recycled and returned to industry [8]. Locally in Nigeria and or Nigerian cities and towns, different researches have been carried out on the challenges o solid wastes in Nigeria and Arica generally, but works on plastic wastes in Nigerian cities and towns are still limited [9]. Developing countries like Nigeria have to import virgin plastic at high cost because recycling activities are usually low in these countries [10]. Machinery available or recycling activities in these countries are usually o very high cost and bulky and as such, recycling activities are restricted by these challenges in these countries. Tereore, Tereore, to overcome these challenges, it was necessary to develop a low cost waste plastic shredding machine using available local materials that can easi ly be operated without much skill or low and medium income earner. earner. Tis will wil l prepare the recycled plastic or the production o new products in Nigeria. Plastic recycling or reprocessing is usually reerred to as the process by which plastic waste material that would otherwise become solid
Int J Waste Resour, an open access journal ISSN: 2252-5211
waste are collected, s eparated, processed and returned to use [11]. Waste Waste plastic shredder is a machine that reduces used plastic bottles to smaller particle sizes to enhance its portability, easiness and readiness or use into another new product. Te design principle o this machine was got rom the ancient tradition method o using scissors to cut materials into reduced orm and scratching used by rabbits when digging or tearing. Tese two traditional methods were applied in the design o the machine by abricating cutting blades to cut the waste plastic while some o the cutting blades have sharp curved edges to draw-in the plastic into the cutting blades teeth. Te waste plastic shredder comprises o our major components, namely; the eeding unit, the shredding unit, the power unit and the machine rame. Te machine can be powered by electric motor o 10 Hp.
Materials and Methods Machine description and operation Te waste plastic shredder has our main components; components; the eeding unit, the shredding unit, the power unit and the machine rame. Te eeding unit is made o 16 – gauge galvanized mild steel sheet o 2 mm thick plate and a dimension o 200 mm × 550 mm through which the waste plastic are ed into the shredding unit. Te shredding unit is where the waste plastic are been cut into smaller sizes. Te unit consists o a shaf, 50 mm length made up o 30 mm mild steel rod and a cylinder o 55 mm length and 200 mm diameter. Attached to
*Corresponding author: Akinresoye WA, Department of Agricultural and Bio-Environmental Engineering Technology, Rufus Giwa Polytechnic, Owo, Ondo State, Nigeria, Tel: + 234-8066217713; Fax: + 234-8066217713; E-mail:
[email protected] Received February 14, 2017; Accepted May 27, 2017; Published June 03, 2017 Citation: Ayo AW, Olukunle OJ, Adelabu DJ (2017) Development of a Waste Plastic Shredding Machine. Int J Waste Resour 7: 281. doi: 10.4172/22525211.1000281 Copyright: © Copyright: © 2017 Ayo AW, et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Volume 7 • Issue 2 • 1000281
Citation: Ayo AW, Olukunle
OJ, Adelabu DJ (2017) Development of a Waste Plastic Shredding Machine. Int J Waste Resour 7: 281. doi: 10.4172/2252-
5211.1000281
Page 2 of 4
the shaf are cutters made o 12 mm mild steel having nine serrated teeth welded 2 mm apart. Te cylinder equally has same cutters with sharp edges to shred the waste plastic. Underneath the shredding unit is the outlet made o 16-gauge galvanised mild steel o 43 mm × 27 mm dimension. Te shredded waste plastic discharge reely rom the shredding unit through the outlet. Te machine is powered by 10 Hp electric motor with the aid o belt and pulley arrangement which has 110 mm diameter driven pulley and 60 mm driver pulley as shown in Figures 1-3.
Design considerations Some o the actors considered in the design o the recycled plastic waste shredding machine are saety, power requirement, compactness, ease o operations and overall cost o production. Material selection based on availability, durability, cost and ease o abrication were also considered.
Design o machine components Feeding chute capacity:
Volume o the hopper = Area o cross-section o the hopper × width o hopper= ½ (a + b) h × width…(1) [12]
Figure 3: Orthographic drawing of shredding machine.
Volume o PE bottle (coca-cola bottle) = 2
Area × height=
Hopper capacity = 2.1 × 10 -2 m3
4
×
h …(2) [13]
= 2.1 × 10-2 /7.7 × 10-4
Volume o PET bottle (coca cola) in the shredding chamber:
No o bottle to fill the hopper = volume o hopper/ volume o PE bottle
π d
Te number o plastic water bottle the hopper will accommodate is 27. Determination o shaf diameter
d3
=
16
(kb mb ) 2 + ( kt mt ) 2 … (3) Hall et al. [14]
πτ
Where, d = diameter o the shaf = 30 mm = allowable shear stress o metal with key way = 40 × 106 N/m2 mb = maximum bending moment = 25.61 Nm mt = torsion moment = 22.3 N Kb = combined shock and atigue actor applied to bending moment = 2.0 (sudden loading) Kt = combined shock and atigue actor applied to torsional moment = 2.0 (sudden loading) Figure 1: Isometric drawing of the shredding machine.
Perormance evaluation procedure One kilogram (1 kg) each o the our different plastic types (Polyethylene erephthalate (PE), the High density polyethylene (HDPE), the Polyvinylchloride (PVC) and the Polypropylene (PP) were shredded at varied motor speed o 1,806.7 rpm, 1,290.5 rpm and 1003.7 rpm using 10 Hp three-phase electric motor as the prime mover. Te shredded waste plastic, Q, was weighed to determine the quantity o the actual shredded waste plastic beore sieving into three different sizes in order to determine their average size and area using Excel 2014. Te Shredding time (), the Specific Mechanical Energy (SME), Troughput (P) and Recovery Efficiency (RE) o the machine were also determined using the relationship below: Specific Mechanical Energy = Power (P) × ime (t)
Figure 2: Exploded view of the shredding machine.
Int J Waste Resour, an open access journal ISSN: 2252-5211
Output mass (Q)
Volume 7 • Issue 2 • 1000281
Citation: Ayo AW, Olukunle
OJ, Adelabu DJ (2017) Development of a Waste Plastic Shredding Machine. Int J Waste Resour 7: 281. doi: 10.4172/2252-
5211.1000281
Page 3 of 4
Troughput (P)=Output mass o recycled waste plastic (Q) ime taken or recycling (t) Recycling Efficiency (RE)= Output mass o recycled waste plastic (Q) × 100 Input mass o waste plastic (I) [10].
Results and Discussion Results Te results obtained rom the machine were presented in ables 1 to 3 while Figure 4 represent the summary o the average size and percentage number o plastic shredded at three variable speed o the motor.
Discussion
PET
HDPE
At the machine speed o 1806.7 rpm, the shredder perormed optimally when shredding PVC with a result o 53.6% shredding achievement while the average shredded size particle is 5.07 mm2. It takes the machine 3 mins to shred the bottle with a recovery efficiency o 95% and the specific mechanical energy was minimal at 392 KJ/kg with a throughput o 19 kg/hr. Tis is ollowed by HDPE with 48% shredded but with an average particle size o 13 mm2 when compared to the particle size o 12.23 mm 2 or PE. At the machine speed o 1290.5 rpm, the shredder still perormed optimally when shredding PVC with 52.8% shredding output within 2 mins and an average shredded size particle o 6.29 mm2. Te SME or PE was urther reduced by 61% when compared to the speed o 1806.7 rpm while the recovery efficiency was 94% and the throughput increases by over 100% to 238.1 KJ/kg which is Tis is ollowed by HDPE and PP
PVC
PP
S/N
Avg size (mm2)
% Shreddd
Avg size (mm2)
% shreddd
Avg size (mm2)
% Shreddd
Avg size (mm2)
% shreddd
1
3.71
28.1
1.01
12.5
0.66
13.4
4.48
13.8
2
8.04
24.6
4.53
28.5
1.89
27.8
11.70
27.7
3
12.23
37.3
13.60
48.0
5.07
53.6
18.05
37.0
Table 1: The result of the shredded plastic at 1806.7 rpm. PET
HDPE
PVC
PP
S/N
Avg size (mm2)
% Shreddd
Avg size (mm2)
% shreddd
Avg size (mm2)
% shreddd
Avg size (mm2)
% shreddd
1
1.07
24.1
0.64
12.6
0.79
14.8
2.12
15.7
2
5.32
27.6
3.25
23.2
1.73
26.7
6.44
30.0
3
10.21
39.4
8.27
48.8
6.29
52.8
14.25
40.0
Table 2: The result of the shredded plastic at 1290.5 rpm. PET
HDPE
PVC
PP
S/N
Avg size (mm2)
% Shreddd
Avg size (mm2)
% shreddd
Avg size (mm2)
% shreddd
Avg size (mm2)
% shreddd
1
0.36
20.1
0.53
13.5
0.93
16.2
0.67
15.1
2
1.89
30.5
2.12
17.4
1.62
25.6
1.18
29.8
3
7.32
41.5
4.58
52.3
7.51
53.3
2.86
40.5
Table 3: The result of the shredded plastic at 1003.7 rpm.
Figure 4: Summary of shredder performance with three speed.
Int J Waste Resour, an open access journal ISSN: 2252-5211
Volume 7 • Issue 2 • 1000281
Citation: Ayo AW, Olukunle
OJ, Adelabu DJ (2017) Development of a Waste Plastic Shredding Machine. Int J Waste Resour 7: 281. doi: 10.4172/2252-
5211.1000281
Page 4 of 4
which has a minimal variance or all the parameters measured.
References
At the machine speed o 1003.7 rpm, 53.3% o PVC plastic was shredded to an average particle size o 7.51 mm 2 within 2 mins. Te specific mechanical energy o the machine at this speed and or PVC reduced by 1% when compared to speed 1806.7 rpm while the recovery efficiency was 95% with throuput o 31.67 kg/hr which is 1% higher than the speed at 1290.5 rpm. Again, the machine shredded 52.3% o HDPE with an average particle size o 4.58 mm2 at this speed within 4 mins with a recovery efficiency o 83%.
1. Shilpi S, Monika S (2013) Eco-Architecture: PET Bottle Houses. International Journal of Scientic Engineering and Technology 2: 1243-1246 .
Conclusion and Recommendation
5. Puttaraj MH, Shanmukha S (2005) Utilization of Waste Plastic In Manufacturing Of Plastic-Soil Bricks. International Journal of Technology Enhancements and Emerging Engineering Research 2: 2347-4289.
Tere was a correlation between the machine speeds with a regression ˂1 and there was a linear relationship with all variable parameters and the operating speed. Troughput capacities o the machine at different shaf speed o 1806.7 rpm, 1290.5 rpm, and 1003.7 rpm were 19.00 kg/hr, 31.33 kg/hr, 31.67 kg/hr respectively. Te recovery efficiencies were up to 95%, 94% and 95% respectively. Te specific mechanical energy was 1077.6 KJ/kg, 1065.7 KJ/kg and 973.0 KJ/kg respectively. Te average particle size was 18.05 mm2, 14.25 mm 2 and 7.51 mm2 respectively and percentage shredded were 53.6%, 52.8% and 53.3% respectively. Te machine thereore has an average Troughput o 27.3 kg/hr, Recovery Efficiency o 95%, Specific Mechanical Energy o 1,039 KJ/kg, Percentage shredded o 53.2% and 95% specifically or PVC type o plastic. Te average particle size shred o 13.3 mm2 and the production cost o the shredding machine is One Hundred and Forty Tousand, Seven Hundred and Fify Naira (N 140,750:00 k) only. Te results obtained rom the waste plastic shredding machine perormance urther shows that the machine could be very useul in a situation where considerable plastics have to be shredded and also efficient in shredding large sizes. Te machine is thereore recommended or use by small and medium scale entrepreneurs working on recycled plastic.
2. Elias HG (2003) An Introduction to Plastics. 3. Metin E, Erozturk A, Neyim C (2003) Solid Waste Management Practises and Review of Recovery and Recycling Operations in Turkey. Waste management 23: 425-432. 4. Winandy JE, Stark NM, Clemons CM (2004) Consideration In Recycling Of Wood- Plastic Composites. 5th Global Wood and Natural Fiber Composites Symposium. Kassel, Germany.
6. Kikuchi R Jan K, Raschman R (2008) Grouping of Mixed Waste Plastics According to Chlorine Content. Separation and Purication Technology 61: 7581. 7. USEPA (2006) Municipal Solid Waste in the United States: 2005 Facts and Figures. Ofcial Report, Municipal and Industrial Solid Waste Division, US Environmental Protection Agency, Washington, DC . 8. Beg MDH, Pickering KL (2008) Reprocessing of wood Fibre Reinforced Polypropylene Composites. Part I: Effects on Physical and Mechanical Properties. Composites Part A Applied Science and Manufacturing 39: 1091– 1100. 9. Aderogba KA, Afelumo AA (2012) Waste Dump and their Management in Lagos Metropolis. Int J Learn Dev 2: 1-16 . 10. Ugoamadi CC, Ihesiulor OK (2011) Optimization of the Development of a Plastic Recycling Machine. Nigerian Journal of Technology. 11. Wienaah MM (2007) Sustainable Plastic Waste Management – A Case of Accra, Ghana. KTH Land and Water Resources Engineering. 12. Fasimirin J (2014) Development of Melon Shelling and Cleaning Machine. Federal University Of Technology Akure, Ondo State, Nigeria. 13. Idemat (2003) Coefcent of Friction. 14. Hall A, Holowenko A, Laughin HC (1980) Theory and Problems of Machine Design.
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Citation: Ayo AW, Olukunle OJ, Adelabu DJ (2017) Development of a Waste Plastic Shredding Machine. Int J Waste Resour 7: 281. doi: 10.4172/22525211.1000281
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